In the summer, the sun is hot and the sun is so hot that everyone working outdoors is mistaken for "African". But recently, the citrus has also been mistaken for an African origin.
If you don't want the fruit to become "orange", you must beware of rusty ticks
The reason why citrus has become "African orange", "monk fruit" and "black peel fruit" is the curse of rusty ticks. Rust ticks, also known as rusty spiders, mainly harm leaves and fruits, and the fruit is more serious. After the fruit is eaten by rusty ticks, it will flow out of the oil, oxidized by the air into a black-brown color, the peel will lose its luster, wood bolting, roughness, and serious cracks will be covered with cracked fine lines, and the fruit will become smaller, lose water, and may also lead to fruit fall!
In addition to affecting the fruit, the leaves are also a favorite of rusty ticks! After the leaf is damaged, it seems to be water-deficient and slightly rolled upwards, and the back of the leaf is smoky yellow or rusty brown, which will affect the photosynthesis of the leaf. At present, in the period of August, just saving nutrients to prepare for next year, rust ticks are not well controlled, which will affect next year's production. So there is a saying that "one year copper, three years poor".
It's small, but it's super raw
Rust ticks are very small in shape, basically invisible to the naked eye, and generally require the help of a magnifying glass. With the help of a magnifying glass or mobile phone to take a picture and zoom in, carefully observe the leaf back and fruit surface, if you find a particularly small insect with dusty surfaces, it is a rust tick.
Rust ticks: Carrot-like insect bodies are visible under a magnifying glass
Rust ticks are "super-born", can breed 24 to 30 generations a year, and do not need a "husband", they can also be born! It's not even a sow! The new shoots begin to climb in May, and the density of the insect population increases rapidly after late June, with the peak period from July to September. And rust ticks are not as afraid of heat as red spiders, and can live well at temperatures of 25 °C-31 °C, which can occur more severely when the climate is dry.
There is no advance prevention, and the golden fruit becomes a copper fruit
Rust ticks were found earlier, which can be controlled in time, such as rust ticks have been serious, then the drug can only control and not continue to deteriorate, can not restore the black peel fruit to its original state, this golden fruit can only become a copper fruit fruit.
Prevention and control methods
★ Prevention
Before the rust tick has occurred, preventive drugs: avermectin, spironyl ester.
★ Treatment
If the rust tick has already borne fruit, you can choose to use lice mite urea to control it.
In the past, the most commonly used agent for the prevention and treatment of rust ticks was butythic Budweiser, which has the effect of touch killing and gastric poisoning, with strong lethality and fast effect. However, due to its long residual effect period, the Ministry of Agriculture and other relevant units have banned the use of butyrosyl budweiser on fruit trees since January 1, 2019.
5% avermectin 1500 times + 5% lice mite urea 1500 times is a better drug regimen in autumn, which can control both rust ticks and leafminer moths, and also has a certain control over red spiders.
Needs attention
★ Bordeaux liquid will kill the natural enemy polychaetes of rusty spiders, rust spiders have serious orchards, less use Bordeaux liquid or copper-containing fungicides.
★ When spraying, it is necessary to spray the inside and lower parts of the canopy first, and then spray the outer and upper parts of the canopy (focusing on the back of the leaves and the shady side of the fruit); be careful and thorough, be sure to spray until the leaves and fruits are wet, generally spray 2-3 times, each time at an interval of 7-10 days.
★ Taking turns to use drugs, changing drugs, red spiders and rust ticks are pests that are very resistant, it is best to kill eggs and kill adult insects mixed, long-acting drugs and quick-acting drugs are used together to avoid making them more resistant to a certain drug.
Source: Great Harvest Citrus Plant Protection